BULLETIN No. 280. 



APRIL, 1912 



Meteorolomcal Observations 



AT THE 



MASSACHUSETTS 



AGlilCULTUML EXPERIMENT 



STATION. 



Latitude, 42" 23' 48.5" N. Longitude 72° 31' 10" W. 



Height of barometer above ground, 51 ft. Above sea level, 2'/j.^ ft. 

 Height of Wind Instnanents 72 ft. 



MONTHLY SUMMARY. 



Pressure. In inches. 



Maxiiuuni reduced to freezing, 3031,26th, 6 a. 

 Minimuiu reduced to freezing, 28.99, 2d, 10:30?. 

 Reduced^ maximum reading, 30.62, 26th, 6 A. 

 Reduced^ minimum reading, 29.30, 2d, 10:30?. 



Mean semi-daily reduced, 29.995 



Monthly range 1.32 



*Air Temperature. In Degrees Fahr. 



Highest 78.0, 6th, 4 p. 



Lowest 24.0, 4th, 7 A. 



Mean hourly, 45-2 



Mean of means of max. and min., .... 46.2 



Mean sensible (wet bulb), 414 



Montlily range, 54-o 



Higliest mean daily 61.8, 6th 



Lowest mean daily, 29-8, 9th 



Mean maximum S^-S 



Mean minimum, 35-7 



Mean daily range 21. i 



Greatest daily range • • " • 42.0, 5th 



Least daily range, 5-5, i4th 



Humidity. 



Mean dew point 37.o 



Mean force of vapor, 308 



Mean relative humidity, 77-2 



Precipitation. In inches. 



Total precipitation, 3-92 



Number of days on which .01 inch or more 



rain fell, • • I7 



Total snow in inches i 



♦Temperature in ground shelter, 

 t Reduced to freezing and sea-level. 



Wind. 



Total movement 6094m. 



Greatest daily movement, .... 419m., 8th 



Least daily movement 52m., 15th 



Mean daily movement 203 ni 



Mean hourly velocity, 8.5 m 



Maximum pressure per square foot, lo.o lbs.= 



45m. per hour, 23d, 12 M., N.W. 

 Maximum velocity for 5 minutes, 33 m. per 



hour, 23d, 10 A., W. N. W. 

 Prevailing Direction, West. 



Summary. 



South Southwest 23 percent. 



Northwest 13 " " 



North 13 " " 



West Northwest 13 " " 



Southwest 10 " " 



Other directions 28 " " 



Weather. 



Mean cloudiness observed, .... 64 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, 204hrs.=5i per cent. 



Number of clear days 5 



Number of fair days, 14 



Number of cloudy days, n 



Bright Sunshine. 



Number of hours recorded, . . 198 hrs.=49* 



Rain, 1st, 2d, 3d, 5th, 7th, Sth, 9th, 12th, 



14th, 15th, 16th, 17th, iSth, 19th, 22d, 24th' 



27th. 29th. 



Snow, 3d, Sth, 9th. 



Late Frosts, 21st, 26th. 



Thunder and Lig: tning, 15th, 16th. 



Hail, 5th, 19th. 



Gales, 35 or more miles per hour : 43m, 7th, 



S.W.; 39m, Sth, W.N.W.: 45m, 23d, N.W. 



35m, 24th, W.S.W.: 37m, 27th, W.N.W. 



